1^4 PEARCE : VARIETIES OF BANDED SNAILS. 



believes a signification to belong to every variation : to use the 

 words of another, we believe that ' there is not a line, nor a 

 spot, nor a colour for which there is not a reason, which has 

 not a purpose or a meaning in the economy of nature." * 



I have gathered together from various localities a good 

 deal of material in the shape of collections oi Helix virgata, Helix 

 caperata, Helix ericetoruin, and Bulimus acutus, together with their 

 numerous varieties, and noted at the time any points connected 

 with any finds that needed to be remembered, as for instance : 

 the surroundings of the molluscs' habitat ; the proportions in 

 which the different species and varieties were associated 

 together. 



Helix caperata is the easiest of the species to deal with, 

 because its variations in form and markings are simpler and less 

 puzzling than is the case with our other banded snails ; and 

 further, the markings of Helix caperata offer us, as I hope to 

 show, with a line of interpretation which, seemingly, may explain 

 the phenomena presented to us in the markings oi Helix virgata, 

 and perhaps too, of Helix ericetoruin and Buliiinis acutus. 

 Primarily, therefore, this paper has to do only with Helix 

 caperata. 



Helix caperata we find to present to our notice variations 

 which fall under the three usual headings : — Variations of Size, 

 of Markings or Colouring, of Form or Shape. The variations 

 in colour or markings will concern us more especially in this 

 paper, but not so as to exclude our noticing first of all the 

 other two classes of variation : — those of Size and those of 

 Form. 



With regard to the Variations in Size, we have as the 

 extreme of largeness the var. ///(ryf;/- (Jeffreys' B.C. Vol. I. p 214), 

 while the extreme towards smallness, which as yet has not been 

 named, would have to be characterized as a var. minor. I think 

 we may venture to suggest the causes which have given rise to 

 these variations. Judging from the fact that the larger forms 



'' Sir Jno. Lubbock. 



J.C, vL, July, 1889. 



